© Learning A–Z All rights reserved. www.sciencea-z.com

Summer 2017

Written by Rhonda Lucas Donald

It’s Knot That Simple

Early Birds Get the Better Breakfast

The Buzz on Pollinating Drones

What’s Inside:

The Moon is directly between Earth and the Sun during a total solar eclipse.

Science Newsinthe

Total Eclipse Sun!

Save the Date: August 21

ofthe

P o w e r e d b y , a d i v i s i o n o f L e a r n i n g A - Z

Credits: Front cover: © Photononstop/Superstock; page 2 (bottom left earth): © iStock/rikkyal; page 2 (top right): © Jeff J Mitchell/Getty Images

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On August 21, many people in the United States are in for a rare treat.

They will be able to see a total eclipse of the Sun. Partial eclipses happen fairly often, but it has been nearly forty years since a total eclipse was visible in the U.S.

What Is a Total Solar Eclipse?During a total solar eclipse, the Moon lines up directly between Earth and the Sun, casting a shadow on Earth. For a few minutes, the Moon completely blocks the Sun from view in some parts of the world. In other places, the Moon only blocks part of the Sun or none of it at all. People in the path of the total eclipse see the Moon’s shadow coming toward them. As the Moon begins to block the Sun, it gets darker outside. Once the Moon has blocked the Sun completely, a thin circle of sunlight peeks out around the edges of the Moon. This is the Sun’s atmosphere, or corona. Usually we can’t see the corona because the Sun’s bright light outshines it.

How to See ItIt is very important that you not look directly at the Sun, even during an eclipse! The light can damage your eyes. Also, never view the Sun through a telescope or binoculars without special solar filters. Instead, use special eclipse glasses or wear welder’s goggles rated 14 or higher. You can also use a pinhole projector to view an image of the eclipse. See the activity on page 4 for instructions.

Where to See ItThe total solar eclipse will not be visible everywhere. The Moon will be exactly between Earth and the Sun only in the “path of totality,” which is just 113 kilometers (70 mi.) wide. Lucky folks from Oregon to South Carolina will be able to see a total solar eclipse—if the sky is clear. People in the rest of North America will see a partial solar eclipse. As the Moon and Earth move, the Moon’s shadow moves, too. The shadow will move across the U.S. from about 9:00 a.m. until 4:00 p.m. The total eclipse will last less than three minutes in each place, so don’t be late for this special event! v

Summer 2017

Total Solar Ecl ipse to Cross U.S.

Special glasses filter sunlight to protect your eyes while watching an eclipse.

This map shows the “path of totality” (thick line) and local times of the total solar eclipse. Outside the path of totality, there will be a partial eclipse. Less and less of the Sun will be covered by the Moon in areas that are farther away from the path of totality.

Portland

Boise

Omaha

St. Louis

New York

Nashville

Charleston

Houston

Los Angeles

10:20 AM

1:00 PM

25%

25%

50%

50%

75%

75%

100%

1:20 PM

2:40 PM

HOW A SOLAR ECLIPSE WORKS

Moon’s orbitNot to scale

Sun

Moon

Earth

MAP OF AUGUST 21, 2017, ECLIPSE

path of totality

SCIENCE in the NEWS

Space Science

Credits: Top: © Alistair Berg/Taxi/Getty Images; bottom: © Nick Dolding/Taxi/Getty Images

© Learning A–Z All rights reserved. www.sciencea-z.com3

Shoelaces can be pesky. They’re always coming untied! Have

you ever wondered why? In a recent study, scientists from the University of California at Berkeley used a high-speed camera to capture the motion of a runner. By examining the images and conducting experiments, they were able to unravel the mystery of the untying knots.

Every step you take results in an impact when your feet hit the ground. The force of these impacts causes the knots in your laces to gradually loosen. Then another force—inertia—pulls at the loose ends of the knot. Inertia is the tendency of an object to keep moving the way it is moving. As you step forward, your laces also move forward. As your foot swings back, your laces are still moving forward at first, due to inertia. These opposing forces tug at the laces, helping them come untied. v

You may have heard the saying, “Early to bed

and early to rise makes you healthy, wealthy, and wise.” New research shows that there might be some truth to this saying.

Some people feel alert when they wake up in the morning. Other people feel tired no matter what time they went to bed. A study of people’s sleep and eating habits found something interesting. Morning people tend to choose nutritious foods that are high in protein and low in sugar. Night owls tend to eat later in the day and choose less nutritious foods that contain more fat and sugar.

The study did not determine whether night owls choose less healthy foods because they can’t sleep or whether they can’t sleep because they eat less nutritious foods. But night owls can benefit from going to bed earlier, eating breakfast earlier, and avoiding junk foods. And whether you’re an early bird or a night owl, it’s wise to choose healthy foods. v

Summer 2017

I t’s Knot That S imple

Early Birds Get the Better Breakfast

Getting up early and eating a healthy breakfast may not make you wealthy, but both habits are good for you.

SCIENCE in the NEWS

Physical Science

Life Science

Credits: Top (both): courtesy of Eijiro Miyako

Proje

ct

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Bees and other pollinators are

in decline. Without them, many plants could not reproduce. We wouldn’t be able to grow all the fruits, vegetables, and nuts that we eat. It’s a serious problem that chemist Eijiro Miyako of Japan wanted to solve.

Miyako invented a sticky gel that he thought might work the way bees’ fuzzy hairs do when they collect pollen. He decided to test his idea using a small drone. He attached hairs from a paintbrush to the underside of the drone and coated them with the gel. It took awhile to master flying the drone, but once he got the hang of it, he was able to use the drone to pollinate flowers in his lab.

One person with a single drone can’t pollinate all our crops. But in the future, one person could use a computer and GPS to program “swarms” of drones to do the job. In fact, the gel could still be useful without the drones. Putting it on other insects, like ants, could allow them to pollinate flowers as bees do! v

The Buzz on Pollinating Drones

Make a simple pinhole projector to safely view an image of the Sun during a solar eclipse. Remember, do not look at the Sun! Stand with your back to the Sun. Use a pushpin to make a small hole in the middle of a white paper plate. Hold this plate above your head and another plate out in front of you. Tilt the plate above your head until an image of the Sun shows up on the plate in front of you.

Write about these questions in your science journal or on separate paper: 1. Why is a pinhole projector useful during a solar eclipse? 2. How can you use a pinhole projector when there is no solar eclipse?

Pinhole Projector

Summer 2017

This illustration shows the pollinating drone moving in toward a lily flower to collect pollen.

Gel-coated hairs under the drone collect pollen from one flower and distribute it to others.

gel-coated hairs

SCIENCE in the NEWS

Technology